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75722d39 BH |
1 | /* |
2 | * Windfarm PowerMac thermal control. Core | |
3 | * | |
4 | * (c) Copyright 2005 Benjamin Herrenschmidt, IBM Corp. | |
5 | * <benh@kernel.crashing.org> | |
6 | * | |
7 | * Released under the term of the GNU GPL v2. | |
8 | * | |
9 | * This core code tracks the list of sensors & controls, register | |
10 | * clients, and holds the kernel thread used for control. | |
11 | * | |
12 | * TODO: | |
13 | * | |
14 | * Add some information about sensor/control type and data format to | |
15 | * sensors/controls, and have the sysfs attribute stuff be moved | |
16 | * generically here instead of hard coded in the platform specific | |
17 | * driver as it us currently | |
18 | * | |
19 | * This however requires solving some annoying lifetime issues with | |
20 | * sysfs which doesn't seem to have lifetime rules for struct attribute, | |
21 | * I may have to create full features kobjects for every sensor/control | |
22 | * instead which is a bit of an overkill imho | |
23 | */ | |
24 | ||
25 | #include <linux/types.h> | |
26 | #include <linux/errno.h> | |
27 | #include <linux/kernel.h> | |
28 | #include <linux/init.h> | |
29 | #include <linux/spinlock.h> | |
75722d39 BH |
30 | #include <linux/kthread.h> |
31 | #include <linux/jiffies.h> | |
32 | #include <linux/reboot.h> | |
33 | #include <linux/device.h> | |
34 | #include <linux/platform_device.h> | |
837e9594 | 35 | #include <linux/mutex.h> |
7dfb7103 | 36 | #include <linux/freezer.h> |
75722d39 | 37 | |
b55fafc5 BH |
38 | #include <asm/prom.h> |
39 | ||
75722d39 BH |
40 | #include "windfarm.h" |
41 | ||
42 | #define VERSION "0.2" | |
43 | ||
44 | #undef DEBUG | |
45 | ||
46 | #ifdef DEBUG | |
47 | #define DBG(args...) printk(args) | |
48 | #else | |
49 | #define DBG(args...) do { } while(0) | |
50 | #endif | |
51 | ||
52 | static LIST_HEAD(wf_controls); | |
53 | static LIST_HEAD(wf_sensors); | |
837e9594 | 54 | static DEFINE_MUTEX(wf_lock); |
e041c683 | 55 | static BLOCKING_NOTIFIER_HEAD(wf_client_list); |
75722d39 BH |
56 | static int wf_client_count; |
57 | static unsigned int wf_overtemp; | |
58 | static unsigned int wf_overtemp_counter; | |
59 | struct task_struct *wf_thread; | |
60 | ||
ac171c46 BH |
61 | static struct platform_device wf_platform_device = { |
62 | .name = "windfarm", | |
63 | }; | |
64 | ||
75722d39 BH |
65 | /* |
66 | * Utilities & tick thread | |
67 | */ | |
68 | ||
69 | static inline void wf_notify(int event, void *param) | |
70 | { | |
e041c683 | 71 | blocking_notifier_call_chain(&wf_client_list, event, param); |
75722d39 BH |
72 | } |
73 | ||
74 | int wf_critical_overtemp(void) | |
75 | { | |
76 | static char * critical_overtemp_path = "/sbin/critical_overtemp"; | |
77 | char *argv[] = { critical_overtemp_path, NULL }; | |
78 | static char *envp[] = { "HOME=/", | |
79 | "TERM=linux", | |
80 | "PATH=/sbin:/usr/sbin:/bin:/usr/bin", | |
81 | NULL }; | |
82 | ||
83 | return call_usermodehelper(critical_overtemp_path, argv, envp, 0); | |
84 | } | |
85 | EXPORT_SYMBOL_GPL(wf_critical_overtemp); | |
86 | ||
87 | static int wf_thread_func(void *data) | |
88 | { | |
89 | unsigned long next, delay; | |
90 | ||
91 | next = jiffies; | |
92 | ||
93 | DBG("wf: thread started\n"); | |
94 | ||
83144186 | 95 | set_freezable(); |
75722d39 | 96 | while(!kthread_should_stop()) { |
75722d39 BH |
97 | if (time_after_eq(jiffies, next)) { |
98 | wf_notify(WF_EVENT_TICK, NULL); | |
99 | if (wf_overtemp) { | |
100 | wf_overtemp_counter++; | |
101 | /* 10 seconds overtemp, notify userland */ | |
102 | if (wf_overtemp_counter > 10) | |
103 | wf_critical_overtemp(); | |
104 | /* 30 seconds, shutdown */ | |
105 | if (wf_overtemp_counter > 30) { | |
106 | printk(KERN_ERR "windfarm: Overtemp " | |
107 | "for more than 30" | |
108 | " seconds, shutting down\n"); | |
109 | machine_power_off(); | |
110 | } | |
111 | } | |
112 | next += HZ; | |
113 | } | |
114 | ||
115 | delay = next - jiffies; | |
116 | if (delay <= HZ) | |
117 | schedule_timeout_interruptible(delay); | |
118 | ||
1ed2ddf3 JB |
119 | /* there should be no non-suspend signal, but oh well */ |
120 | if (signal_pending(current) && !try_to_freeze()) { | |
75722d39 BH |
121 | printk(KERN_WARNING "windfarm: thread got sigl !\n"); |
122 | break; | |
123 | } | |
124 | } | |
125 | ||
126 | DBG("wf: thread stopped\n"); | |
127 | ||
128 | return 0; | |
129 | } | |
130 | ||
131 | static void wf_start_thread(void) | |
132 | { | |
133 | wf_thread = kthread_run(wf_thread_func, NULL, "kwindfarm"); | |
134 | if (IS_ERR(wf_thread)) { | |
135 | printk(KERN_ERR "windfarm: failed to create thread,err %ld\n", | |
136 | PTR_ERR(wf_thread)); | |
137 | wf_thread = NULL; | |
138 | } | |
139 | } | |
140 | ||
141 | ||
142 | static void wf_stop_thread(void) | |
143 | { | |
144 | if (wf_thread) | |
145 | kthread_stop(wf_thread); | |
146 | wf_thread = NULL; | |
147 | } | |
148 | ||
149 | /* | |
150 | * Controls | |
151 | */ | |
152 | ||
153 | static void wf_control_release(struct kref *kref) | |
154 | { | |
155 | struct wf_control *ct = container_of(kref, struct wf_control, ref); | |
156 | ||
157 | DBG("wf: Deleting control %s\n", ct->name); | |
158 | ||
159 | if (ct->ops && ct->ops->release) | |
160 | ct->ops->release(ct); | |
161 | else | |
162 | kfree(ct); | |
163 | } | |
164 | ||
ac171c46 BH |
165 | static ssize_t wf_show_control(struct device *dev, |
166 | struct device_attribute *attr, char *buf) | |
167 | { | |
168 | struct wf_control *ctrl = container_of(attr, struct wf_control, attr); | |
169 | s32 val = 0; | |
170 | int err; | |
171 | ||
172 | err = ctrl->ops->get_value(ctrl, &val); | |
173 | if (err < 0) | |
174 | return err; | |
175 | return sprintf(buf, "%d\n", val); | |
176 | } | |
177 | ||
178 | /* This is really only for debugging... */ | |
179 | static ssize_t wf_store_control(struct device *dev, | |
180 | struct device_attribute *attr, | |
181 | const char *buf, size_t count) | |
182 | { | |
183 | struct wf_control *ctrl = container_of(attr, struct wf_control, attr); | |
184 | int val; | |
185 | int err; | |
186 | char *endp; | |
187 | ||
188 | val = simple_strtoul(buf, &endp, 0); | |
189 | while (endp < buf + count && (*endp == ' ' || *endp == '\n')) | |
190 | ++endp; | |
191 | if (endp - buf < count) | |
192 | return -EINVAL; | |
193 | err = ctrl->ops->set_value(ctrl, val); | |
194 | if (err < 0) | |
195 | return err; | |
196 | return count; | |
197 | } | |
198 | ||
75722d39 BH |
199 | int wf_register_control(struct wf_control *new_ct) |
200 | { | |
201 | struct wf_control *ct; | |
202 | ||
837e9594 | 203 | mutex_lock(&wf_lock); |
75722d39 BH |
204 | list_for_each_entry(ct, &wf_controls, link) { |
205 | if (!strcmp(ct->name, new_ct->name)) { | |
206 | printk(KERN_WARNING "windfarm: trying to register" | |
207 | " duplicate control %s\n", ct->name); | |
837e9594 | 208 | mutex_unlock(&wf_lock); |
75722d39 BH |
209 | return -EEXIST; |
210 | } | |
211 | } | |
212 | kref_init(&new_ct->ref); | |
213 | list_add(&new_ct->link, &wf_controls); | |
214 | ||
ac171c46 | 215 | new_ct->attr.attr.name = new_ct->name; |
ac171c46 BH |
216 | new_ct->attr.attr.mode = 0644; |
217 | new_ct->attr.show = wf_show_control; | |
218 | new_ct->attr.store = wf_store_control; | |
ccd308f0 SR |
219 | if (device_create_file(&wf_platform_device.dev, &new_ct->attr)) |
220 | printk(KERN_WARNING "windfarm: device_create_file failed" | |
221 | " for %s\n", new_ct->name); | |
222 | /* the subsystem still does useful work without the file */ | |
ac171c46 | 223 | |
75722d39 BH |
224 | DBG("wf: Registered control %s\n", new_ct->name); |
225 | ||
226 | wf_notify(WF_EVENT_NEW_CONTROL, new_ct); | |
837e9594 | 227 | mutex_unlock(&wf_lock); |
75722d39 BH |
228 | |
229 | return 0; | |
230 | } | |
231 | EXPORT_SYMBOL_GPL(wf_register_control); | |
232 | ||
233 | void wf_unregister_control(struct wf_control *ct) | |
234 | { | |
837e9594 | 235 | mutex_lock(&wf_lock); |
75722d39 | 236 | list_del(&ct->link); |
837e9594 | 237 | mutex_unlock(&wf_lock); |
75722d39 BH |
238 | |
239 | DBG("wf: Unregistered control %s\n", ct->name); | |
240 | ||
241 | kref_put(&ct->ref, wf_control_release); | |
242 | } | |
243 | EXPORT_SYMBOL_GPL(wf_unregister_control); | |
244 | ||
245 | struct wf_control * wf_find_control(const char *name) | |
246 | { | |
247 | struct wf_control *ct; | |
248 | ||
837e9594 | 249 | mutex_lock(&wf_lock); |
75722d39 BH |
250 | list_for_each_entry(ct, &wf_controls, link) { |
251 | if (!strcmp(ct->name, name)) { | |
252 | if (wf_get_control(ct)) | |
253 | ct = NULL; | |
837e9594 | 254 | mutex_unlock(&wf_lock); |
75722d39 BH |
255 | return ct; |
256 | } | |
257 | } | |
837e9594 | 258 | mutex_unlock(&wf_lock); |
75722d39 BH |
259 | return NULL; |
260 | } | |
261 | EXPORT_SYMBOL_GPL(wf_find_control); | |
262 | ||
263 | int wf_get_control(struct wf_control *ct) | |
264 | { | |
265 | if (!try_module_get(ct->ops->owner)) | |
266 | return -ENODEV; | |
267 | kref_get(&ct->ref); | |
268 | return 0; | |
269 | } | |
270 | EXPORT_SYMBOL_GPL(wf_get_control); | |
271 | ||
272 | void wf_put_control(struct wf_control *ct) | |
273 | { | |
274 | struct module *mod = ct->ops->owner; | |
275 | kref_put(&ct->ref, wf_control_release); | |
276 | module_put(mod); | |
277 | } | |
278 | EXPORT_SYMBOL_GPL(wf_put_control); | |
279 | ||
280 | ||
281 | /* | |
282 | * Sensors | |
283 | */ | |
284 | ||
285 | ||
286 | static void wf_sensor_release(struct kref *kref) | |
287 | { | |
288 | struct wf_sensor *sr = container_of(kref, struct wf_sensor, ref); | |
289 | ||
290 | DBG("wf: Deleting sensor %s\n", sr->name); | |
291 | ||
292 | if (sr->ops && sr->ops->release) | |
293 | sr->ops->release(sr); | |
294 | else | |
295 | kfree(sr); | |
296 | } | |
297 | ||
ac171c46 BH |
298 | static ssize_t wf_show_sensor(struct device *dev, |
299 | struct device_attribute *attr, char *buf) | |
300 | { | |
301 | struct wf_sensor *sens = container_of(attr, struct wf_sensor, attr); | |
302 | s32 val = 0; | |
303 | int err; | |
304 | ||
305 | err = sens->ops->get_value(sens, &val); | |
306 | if (err < 0) | |
307 | return err; | |
308 | return sprintf(buf, "%d.%03d\n", FIX32TOPRINT(val)); | |
309 | } | |
310 | ||
75722d39 BH |
311 | int wf_register_sensor(struct wf_sensor *new_sr) |
312 | { | |
313 | struct wf_sensor *sr; | |
314 | ||
837e9594 | 315 | mutex_lock(&wf_lock); |
75722d39 BH |
316 | list_for_each_entry(sr, &wf_sensors, link) { |
317 | if (!strcmp(sr->name, new_sr->name)) { | |
318 | printk(KERN_WARNING "windfarm: trying to register" | |
319 | " duplicate sensor %s\n", sr->name); | |
837e9594 | 320 | mutex_unlock(&wf_lock); |
75722d39 BH |
321 | return -EEXIST; |
322 | } | |
323 | } | |
324 | kref_init(&new_sr->ref); | |
325 | list_add(&new_sr->link, &wf_sensors); | |
326 | ||
ac171c46 | 327 | new_sr->attr.attr.name = new_sr->name; |
ac171c46 BH |
328 | new_sr->attr.attr.mode = 0444; |
329 | new_sr->attr.show = wf_show_sensor; | |
330 | new_sr->attr.store = NULL; | |
ccd308f0 SR |
331 | if (device_create_file(&wf_platform_device.dev, &new_sr->attr)) |
332 | printk(KERN_WARNING "windfarm: device_create_file failed" | |
333 | " for %s\n", new_sr->name); | |
334 | /* the subsystem still does useful work without the file */ | |
ac171c46 | 335 | |
75722d39 BH |
336 | DBG("wf: Registered sensor %s\n", new_sr->name); |
337 | ||
338 | wf_notify(WF_EVENT_NEW_SENSOR, new_sr); | |
837e9594 | 339 | mutex_unlock(&wf_lock); |
75722d39 BH |
340 | |
341 | return 0; | |
342 | } | |
343 | EXPORT_SYMBOL_GPL(wf_register_sensor); | |
344 | ||
345 | void wf_unregister_sensor(struct wf_sensor *sr) | |
346 | { | |
837e9594 | 347 | mutex_lock(&wf_lock); |
75722d39 | 348 | list_del(&sr->link); |
837e9594 | 349 | mutex_unlock(&wf_lock); |
75722d39 BH |
350 | |
351 | DBG("wf: Unregistered sensor %s\n", sr->name); | |
352 | ||
353 | wf_put_sensor(sr); | |
354 | } | |
355 | EXPORT_SYMBOL_GPL(wf_unregister_sensor); | |
356 | ||
357 | struct wf_sensor * wf_find_sensor(const char *name) | |
358 | { | |
359 | struct wf_sensor *sr; | |
360 | ||
837e9594 | 361 | mutex_lock(&wf_lock); |
75722d39 BH |
362 | list_for_each_entry(sr, &wf_sensors, link) { |
363 | if (!strcmp(sr->name, name)) { | |
364 | if (wf_get_sensor(sr)) | |
365 | sr = NULL; | |
837e9594 | 366 | mutex_unlock(&wf_lock); |
75722d39 BH |
367 | return sr; |
368 | } | |
369 | } | |
837e9594 | 370 | mutex_unlock(&wf_lock); |
75722d39 BH |
371 | return NULL; |
372 | } | |
373 | EXPORT_SYMBOL_GPL(wf_find_sensor); | |
374 | ||
375 | int wf_get_sensor(struct wf_sensor *sr) | |
376 | { | |
377 | if (!try_module_get(sr->ops->owner)) | |
378 | return -ENODEV; | |
379 | kref_get(&sr->ref); | |
380 | return 0; | |
381 | } | |
382 | EXPORT_SYMBOL_GPL(wf_get_sensor); | |
383 | ||
384 | void wf_put_sensor(struct wf_sensor *sr) | |
385 | { | |
386 | struct module *mod = sr->ops->owner; | |
387 | kref_put(&sr->ref, wf_sensor_release); | |
388 | module_put(mod); | |
389 | } | |
390 | EXPORT_SYMBOL_GPL(wf_put_sensor); | |
391 | ||
392 | ||
393 | /* | |
394 | * Client & notification | |
395 | */ | |
396 | ||
397 | int wf_register_client(struct notifier_block *nb) | |
398 | { | |
399 | int rc; | |
400 | struct wf_control *ct; | |
401 | struct wf_sensor *sr; | |
402 | ||
837e9594 | 403 | mutex_lock(&wf_lock); |
e041c683 | 404 | rc = blocking_notifier_chain_register(&wf_client_list, nb); |
75722d39 BH |
405 | if (rc != 0) |
406 | goto bail; | |
407 | wf_client_count++; | |
408 | list_for_each_entry(ct, &wf_controls, link) | |
409 | wf_notify(WF_EVENT_NEW_CONTROL, ct); | |
410 | list_for_each_entry(sr, &wf_sensors, link) | |
411 | wf_notify(WF_EVENT_NEW_SENSOR, sr); | |
412 | if (wf_client_count == 1) | |
413 | wf_start_thread(); | |
414 | bail: | |
837e9594 | 415 | mutex_unlock(&wf_lock); |
75722d39 BH |
416 | return rc; |
417 | } | |
418 | EXPORT_SYMBOL_GPL(wf_register_client); | |
419 | ||
420 | int wf_unregister_client(struct notifier_block *nb) | |
421 | { | |
837e9594 | 422 | mutex_lock(&wf_lock); |
e041c683 | 423 | blocking_notifier_chain_unregister(&wf_client_list, nb); |
75722d39 BH |
424 | wf_client_count++; |
425 | if (wf_client_count == 0) | |
426 | wf_stop_thread(); | |
837e9594 | 427 | mutex_unlock(&wf_lock); |
75722d39 BH |
428 | |
429 | return 0; | |
430 | } | |
431 | EXPORT_SYMBOL_GPL(wf_unregister_client); | |
432 | ||
433 | void wf_set_overtemp(void) | |
434 | { | |
837e9594 | 435 | mutex_lock(&wf_lock); |
75722d39 BH |
436 | wf_overtemp++; |
437 | if (wf_overtemp == 1) { | |
438 | printk(KERN_WARNING "windfarm: Overtemp condition detected !\n"); | |
439 | wf_overtemp_counter = 0; | |
440 | wf_notify(WF_EVENT_OVERTEMP, NULL); | |
441 | } | |
837e9594 | 442 | mutex_unlock(&wf_lock); |
75722d39 BH |
443 | } |
444 | EXPORT_SYMBOL_GPL(wf_set_overtemp); | |
445 | ||
446 | void wf_clear_overtemp(void) | |
447 | { | |
837e9594 | 448 | mutex_lock(&wf_lock); |
75722d39 BH |
449 | WARN_ON(wf_overtemp == 0); |
450 | if (wf_overtemp == 0) { | |
837e9594 | 451 | mutex_unlock(&wf_lock); |
75722d39 BH |
452 | return; |
453 | } | |
454 | wf_overtemp--; | |
455 | if (wf_overtemp == 0) { | |
456 | printk(KERN_WARNING "windfarm: Overtemp condition cleared !\n"); | |
457 | wf_notify(WF_EVENT_NORMALTEMP, NULL); | |
458 | } | |
837e9594 | 459 | mutex_unlock(&wf_lock); |
75722d39 BH |
460 | } |
461 | EXPORT_SYMBOL_GPL(wf_clear_overtemp); | |
462 | ||
463 | int wf_is_overtemp(void) | |
464 | { | |
465 | return (wf_overtemp != 0); | |
466 | } | |
467 | EXPORT_SYMBOL_GPL(wf_is_overtemp); | |
468 | ||
75722d39 BH |
469 | static int __init windfarm_core_init(void) |
470 | { | |
471 | DBG("wf: core loaded\n"); | |
472 | ||
b55fafc5 BH |
473 | /* Don't register on old machines that use therm_pm72 for now */ |
474 | if (machine_is_compatible("PowerMac7,2") || | |
475 | machine_is_compatible("PowerMac7,3") || | |
476 | machine_is_compatible("RackMac3,1")) | |
477 | return -ENODEV; | |
75722d39 BH |
478 | platform_device_register(&wf_platform_device); |
479 | return 0; | |
480 | } | |
481 | ||
482 | static void __exit windfarm_core_exit(void) | |
483 | { | |
484 | BUG_ON(wf_client_count != 0); | |
485 | ||
486 | DBG("wf: core unloaded\n"); | |
487 | ||
488 | platform_device_unregister(&wf_platform_device); | |
489 | } | |
490 | ||
491 | ||
492 | module_init(windfarm_core_init); | |
493 | module_exit(windfarm_core_exit); | |
494 | ||
495 | MODULE_AUTHOR("Benjamin Herrenschmidt <benh@kernel.crashing.org>"); | |
496 | MODULE_DESCRIPTION("Core component of PowerMac thermal control"); | |
497 | MODULE_LICENSE("GPL"); | |
498 |